Module 9 14 Fluoroquinolones Flashcards
Question
Answer
What are fluoroquinolones, and what is their relationship to nalidixic acid?
Fluoroquinolones are fluorinated analogs of nalidixic acid. While nalidixic acid is a narrow-spectrum antibiotic for UTIs, fluoroquinolones are broad-spectrum agents with multiple applications.
How do fluoroquinolones benefit patients?
The benefits of fluoroquinolones arise from their ability to disrupt DNA replication and cell division.
What cellular processes are not affected by fluoroquinolones?
Fluoroquinolones do not interfere with protein synthesis or cell wall synthesis in bacteria.
How can systemic fluoroquinolones be administered?
All systemic fluoroquinolones can be administered orally, making them attractive alternatives to intravenous therapy in many cases.
What is a rare but known side effect associated with fluoroquinolones?
Tendinitis and tendon rupture, often involving the Achilles tendon, are rare side effects of fluoroquinolones.
Why are fluoroquinolones no longer recommended for treating Neisseria gonorrhoeae infections?
Bacterial resistance has become common in Neisseria gonorrhoeae, making fluoroquinolones ineffective for this infection.
Name some systemic fluoroquinolone antibiotics.
Systemic fluoroquinolones include ciprofloxacin (Cipro), levofloxacin (Levaquin), ofloxacin, moxifloxacin (Avelox), gemifloxacin (Factive), and delafloxacin (Baxdela).
What are the common therapeutic uses of systemic fluoroquinolones?
Systemic fluoroquinolones are used to treat infections in the respiratory tract, urinary tract, GI tract, skin and soft tissues. They are also employed for inhalational anthrax in some cases.
What are the general pharmacokinetic characteristics of these drugs?
Most systemic fluoroquinolones undergo hepatic metabolism and renal elimination. CSF absorption is often poor.
What are the common adverse effects associated with systemic fluoroquinolones?
Common adverse effects include tendonitis and tendon rupture, phototoxicity, exacerbation of muscle weakness in myasthenia gravis (MG), peripheral neuropathy, and the potential to prolong the QT interval.
What are some notable drug interactions with systemic fluoroquinolones?
Drug interactions can occur when these antibiotics are taken with antacids, calcium supplements, milk and dairy products, iron salts, zinc salts, and sucralfate.
How do the pharmacokinetics of levofloxacin, ofloxacin, gemifloxacin, and delafloxacin differ?
Levofloxacin has minimal hepatic metabolism, while ofloxacin and gemifloxacin have minimal hepatic metabolism and primary renal elimination. Delafloxacin has hepatic metabolism and primary renal elimination, with secondary elimination in the GI tract (feces).
What is ciprofloxacin, and what is its significance in the context of fluoroquinolone antibiotics?
Ciprofloxacin (Cipro) is one of the early fluoroquinolone antibiotics and serves as a prototype for the class.
What spectrum of bacterial pathogens is ciprofloxacin effective against?
Ciprofloxacin is effective against a broad spectrum of bacterial pathogens.
In what forms can ciprofloxacin be administered?
Ciprofloxacin can be administered orally or intravenously.
For what purpose has oral ciprofloxacin been used as an alternative to intravenous antibiotics?
Oral ciprofloxacin has been employed as an alternative to intravenous antibiotics for the treatment of various serious infections.
What is a significant advantage of using oral ciprofloxacin for treatment?
One of the advantages is that patients receiving oral ciprofloxacin can be treated at home rather than requiring hospitalization for intravenous antibacterial therapy.
What is the classification of Ciprofloxacin?
Ciprofloxacin belongs to the fluoroquinolone class of antibiotics.
Which antibiotic is categorized as a nitroimidazole?
Metronidazole is classified as a nitroimidazole antibiotic.
To which class of antibiotics does Daptomycin belong?
Daptomycin falls under the category of cyclic lipopeptide antibiotics.
What are the two bacterial enzymes inhibited by ciprofloxacin?
Ciprofloxacin inhibits DNA gyrase and topoisomerase IV in bacteria.
How does DNA gyrase play a role in DNA replication?
DNA gyrase converts closed circular DNA into a supercoiled form, which is essential for DNA replication.
How does topoisomerase IV contribute to bacterial cell division?
Topoisomerase IV helps separate daughter DNA strands during bacterial cell division.
How does ciprofloxacin’s action on DNA gyrase and topoisomerase IV affect bacteria?
Ciprofloxacin disrupts DNA replication and cell division in bacteria, making it bactericidal.
Why are host cells spared from the effects of ciprofloxacin?
The mammalian equivalents of DNA gyrase and topoisomerase IV are largely insensitive to fluoroquinolones, which prevents damage to host cells.
What is the spectrum of bacterial activity for ciprofloxacin?
Ciprofloxacin has a broad spectrum of bacterial activity.
Which types of bacteria are ciprofloxacin most effective against?
Ciprofloxacin is highly effective against most aerobic gram-negative bacteria and some gram-positive bacteria.
Name some specific bacterial pathogens that are sensitive to ciprofloxacin.
Sensitive pathogens include Escherichia coli, Klebsiella species, Salmonella, Shigella, Campylobacter jejuni, Bacillus anthracis, Pseudomonas aeruginosa, Haemophilus influenzae, meningococci, and various streptococci.
How does ciprofloxacin perform against anaerobic bacteria?
Ciprofloxacin’s activity against anaerobic bacteria ranges from fair to poor.
What is the available routes of administration for ciprofloxacin?
Ciprofloxacin can be administered orally or intravenously.
How does ciprofloxacin behave after oral dosing in terms of absorption?
Ciprofloxacin is rapidly absorbed after oral dosing, but the absorption is incomplete.
In which body tissues or fluids are high concentrations of ciprofloxacin achieved?
High concentrations of ciprofloxacin are found in urine, stool, bile, saliva, bone, and prostate tissue.
What is the level of ciprofloxacin in cerebrospinal fluid (CSF)?
Ciprofloxacin levels in cerebrospinal fluid (CSF) are low.
